add travis status image to docs
add travis status image to docs
TheOpenDevProject/gmusicapi,nvbn/Unofficial-Google-Music-API,thebigmunch/gmusicapi,dvirtz/gmusicapi,jimyx17/gmusic,tanhaiwang/gmusicapi,dvirtz/gmusicapi,simon-weber/Unofficial-Google-Music-API,peetahzee/Unofficial-Google-Music-API,simon-weber/gmusicapi